The present application claims priority under 35 U.S.C. xc2xa7119 of German Patent Application No. 199 00 986.4, filed on Jan. 13, 1999, the disclosure of which is expressly incorporated by reference herein in its entirety.
1. Field of the Invention
The present invention relates to a process for transferring a traveling material web, e.g., a paper web, into a target region, e.g., onto a target roll, in which a transfer strip that extends approximately parallel to a travel direction of the material web is cut in the traveling material web by at least two cutting mechanisms that can be moved relative to the material web in a plane that is approximately parallel to material web.
The present invention also relates to a device for transferring a traveling material web, e.g., a paper web, having at least two cutting mechanisms that can be moved relative to the material web in a plane approximately parallel to the material web, which are adapted to cut a transfer strip that extends approximately parallel to the travel direction of the material web.
2. Discussion of Background Information
Processes and devices of the type generally discussed above are used, e.g., in paper manufacturing to supply the new web beginning to a target roll, e.g., when a paper machine is being started up or after the paper web tears. The target roll is formed as, e.g., a web guide roll either that deflects the paper web or onto which the paper web is to be wound.
International Publication No. WO 98/33974 discloses a process and a device for producing an insertion strip in a paper machine. This document discloses cutting a narrow edge strip in the web by one of two cutting devices and then moving the cutting device together with another cutting device toward a middle of the web. As a result, the web is cut starting from the web edge by the second cutting device. Thus, the free edge strip is produced and conveyed into a pulper while the insertion strip is blown onto a conveyor device that extends laterally to the web. However, this document does not disclose how the beginning of the insertion strip is produced.
International Publication No. WO 97/48632 discloses using two cuts that start approximately from a center of a paper web and which end at opposite web edges. The cuts are produced by a water jet that is discharged by a movable nozzle so as to broaden out the new web beginning without producing a transfer strip. The cuts can have a common starting point so that the web is completely severed. Then, strip-shaped adhesive surfaces are applied either to the new web beginning or to a roll onto which the paper web is to be wound so that the new web beginning adheres when it touches the roll.
The present invention provides a process and a device of the type mentioned generally discussed above which also permits as simple and reliable as possible a transfer of the traveling material web.
In particular, the process also includes cutting a pointed beginning of the transfer strip. In this regard, at least one of the cutting mechanisms is moved in the direction of one of the web edges from a width position of the cutting mechanisms. In this way, cuts are produced that are at least approximately identical or which can extend at least in close proximity to each other with respect to a width position.
Due to the at least approximately identical width position of the cutting mechanisms, the present invention permits the cuts, which are produced by the cutting mechanisms, to coincide or at least to extend in close proximity to one another either at a point or over a particular length. Thus, the beginning of the transfer strip can be cut out of the traveling material web so that a free strip beginning is produced which can be easily supplied to the target region.
Another essential advantage of the present invention is that a same width position can be selected in a basically arbitrary fashion so that the strip beginning can be cut out at an arbitrary location across the width of the material web. Thus, according to the instant invention, one is not limited to a conveyor device located next to the material web, such as a cable pull. The conveyor device for the transfer strip can therefore also be disposed, e.g., in the center of the material web.
The present invention permits an optimal matching of both the position and the width of the transfer strip to a concrete design of the conveyor device and to the plane in which the conveyor device is located. In this way, it can be particularly advantageous for the matching to be reproducible. Furthermore, the invention permits the cutting of the transfer strip to start inside the material web, i.e, it is not necessary start the cutting from one of the web edges. Thus, the present invention eliminates the need to produce a free edge strip, which must be carried out in a definite manner at a comparatively high cost and must, e.g., be blown into the pulper.
According to an exemplary embodiment of the invention, the cutting mechanism(s) can be moved such that cuts produced by the cutting mechanisms cross over each other.
In this way, the beginning of the transfer strip can be cut out from the material web, and the cutting mechanisms can switch positions, i.e., viewed in terms of the width of the material web. Further advantages can be found in that, in the event that a preceding transfer attempt has failed, recutting of a strip beginning can be made by switching (exchanging) positions of the cutting mechanisms, which avoids a time-consuming return of the cutting mechanisms into a starting position. Furthermore, before cutting the transfer strip, i.e, before producing the criss-crossing cuts, a leader strip that precedes the transfer strip can be cut in the material web using the two cutting mechanisms. A significant advantage of the invention is that the end of the leader strip is completely cut out or separated by the criss-crossing cuts, i.e, is severed from the new web beginning. According to the invention, this severing of the leader strip, which is also referred to as severing of the remainder strip, is carried out automatically using the beginning of the transfer strip.
According to another exemplary embodiment of the invention, the cutting mechanisms can be moved so that cuts at the strip beginning produced by the cutting mechanisms, e.g., at the tip of the strip, are routed past one another at close proximity in such a way that an intended tear point is produced.
In this way, an automatic production of a free beginning of the transfer strip can be performed without requiring the execution of cuts, e.g., which cross one another or which start from a single cut in order to cut out the strip beginning.
According to another exemplary embodiment of the invention, the strip beginning can be supplied to the target region and/or to a conveyor device at least essentially immediately after the cutting of the transfer strip is begun.
This procedure actually becomes possible due to the fact that the beginning of the transfer strip is cut out of the material web. One advantage of the early manipulation of the strip beginning is that, as a result, the transfer strip can be moved at least approximately along an ideal web travel path between the cutting mechanisms and the target region along which web travel path, e.g., the material web is guided during normal operation.
The present invention also provides a device to cut a pointed beginning of the transfer strip in which at least one of the cutting mechanisms can be moved in the direction of one of the web edges from a width position of the cutting mechanisms. The moving width position produces cuts that are at least approximately identical and at least extend in close proximity to the cuts of the other cutting mechanism.
The present invention is directed to a process for transferring a traveling material web into a target region. The process includes positioning at least two cutting mechanisms at one of a same and different width positions between web edges of a traveling material web. The at least two cutting mechanisms are movable relative to the traveling material web in a plane approximately parallel to the material web. The process also includes cutting the traveling material web at the one of the same and different width positions, thereby forming at least one resulting cut that extends approximately parallel to a web travel direction, and forming a substantially pointed beginning of a transfer strip by moving at least one of the at least two cutting mechanisms in a direction toward one of the web edges from its respective width position. In this manner, the resulting cuts of the at least two cutting mechanisms occur at one of a same and a substantially close proximity to a same width position.
In accordance with a feature of the present invention, the resulting cuts of the at least two cutting mechanisms at the strip beginning can have a common starting point. Further, the common starting point may be at a downstream tip of the transfer strip relative to the web travel direction.
According to another feature of the instant invention, the resulting cuts of the at least two cutting mechanisms can cross each other.
Before forming the substantially pointed beginning of the transfer strip, the at least two cutting mechanisms can form only a single cut. Further, the single cut may extend approximately parallel to the web travel direction.
The at least two cutting mechanisms may be coupled for rotation about an axis normal to the traveling material web. The at least two cutting mechanisms can be positionable into different width positions, and, when rotated around the axis by approximately 90xc2x0, the at least two cutting mechanisms may be positionable in a same width position.
According to still another feature of the invention, at the strip beginning, the resulting cuts produced by the at least two cutting mechanisms may be guided in close proximity to one another, thereby forming an intended tear point. The tear point may be formed at the tip of the strip.
In accordance with a further feature of the present invention, the transfer strip can be cut approximately from the center of the traveling material web.
As a further feature of the instant invention, the transfer strip can be formed to have a width which is small relative to a width of the traveling material web and which can be at least approximately constant.
After the formation of the transfer strip, the process may further include moving the at least two cutting mechanisms away from each other in directions toward the web edges.
In accordance with another feature of the invention, the at least one cutting mechanism may be movable essentially cross-wise to the web travel direction.
The process can further include cutting a leader strip prior to forming the transfer strip. The leader strip may be parallel to the web travel direction and may be positioned in close proximity to one of the web edges.
According to a still further feature of the instant invention, remaining portions of the traveling material web located adjacent to the transfer strip may be guided into one of a machine basement and pulper of a paper machine.
The process may further include supplying the transfer strip to at least one of the target region and a conveyor device at least essentially immediately after the forming of the pointed beginning of the transfer strip.
Moreover, the process can also include moving the transfer strip at least approximately along an ideal web travel path between the at least two cutting mechanisms and the target region.
According to another feature of the invention, the traveling material web may be cut in a supported region. The support region can be formed by at least one of a roll and a wire.
In accordance with still another feature, the traveling material web may be cut in an unsupported region. The unsupported region may be a free draw located immediately before a roll.
The at least two cutting mechanisms can include nozzles for discharging a fluid jet. The fluid jet may include a water jet, and the fluid jet may be discharged obliquely to a direction normal of the traveling material web.
In accordance with another feature of the invention, the traveling material web can be composed of a paper web.
According to yet another feature, the target region can include a target roll.
The present invention is directed to an apparatus for transferring a traveling material web. The apparatus includes at least two cutting mechanisms which are movable relative to the traveling material web in a plane approximately parallel to traveling material web, and the at least two cutting mechanisms are positioned to cut a transfer strip that extends approximately parallel to a web travel direction. The at least two cutting mechanisms are positionable at one of a same and different width positions between web edges of the traveling material web to produce at least one resulting cut in the traveling material web, and at least one of the at least two cutting mechanisms is movable toward an edge of the traveling web to form a pointed beginning of a transfer strip. In this manner, the resulting cuts of the at least two cutting mechanisms occur at one of a same and a substantially close proximity to a same width position.
According to a feature of the instant invention, the at least two cutting mechanisms are movable independently of each other.
In accordance with another feature of the invention, the at least two cutting mechanisms can be positioned with an approximately constant spacing in the web travel direction, and may be movable along a common axis cross-wise to the web travel direction.
The at least two cutting mechanisms can be located on a common carrier which extends across the traveling material web in a cross-wise direction.
Moreover, the at least two cutting mechanisms may be rotatable around an axis that extends approximately normal to the traveling material web.
Further, the at least two cutting mechanisms can include at least one nozzle for discharging a fluid jet. The fluid jet can include a water jet, and the fluid jet may be discharged obliquely to a direction normal of the traveling material web.
According to yet another feature of the instant invention, the apparatus can form a component of one of a drying section, a wet section, a coating unit, and an end group of a paper machine.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.